Mixin VS fabric-example-mod

And one day maybe you'll need that to inject code into specific location, but it's to do advanced things: https://github.com/SpongePowered/Mixin/wiki

SpongePowered isn't a Mod, they're the group that maintain the Framework for Mixins. The next mod in the stacktrace is cpw.mods.modlauncher

That source was probably outdated. Forge didn't natively allow you to do that. You could do Java voodoo to allow a library that implemented(? Not sure if it implemented the feature or simply allowed it to be used in a specific way) Mixins, those allow you to modify the game's bytecode. Modern Forge has that library natively. Source: First paragraph of https://github.com/SpongePowered/Mixin/wiki/Mixins-on-Minecraft-Forge

These days Mojang provides obfuscation maps, so you can work with proper class and method names (though no parameter or local variable names). There's also been a lot of effort been put into the tooling. Nowadays there exists Gradle plugins that will download the game jar, decompile it and deobfuscate it using the official mappings. You develop against the deobfuscated code, then the plugin will turn the unobfuscated names back into their obfuscated versions when you compile. There's also been technology developed that lets you easily modify specific parts of a method in the game, so you can e.g. insert calls to your own functions at runtime.[1] This saves from you having to modify the game jar itself.

[1]: https://github.com/SpongePowered/Mixin

quilt (and fabric) take mojang's jar and preprocess it similarly, but the rest of the modifications to the code are done at runtime using a ridiculously powerful instrumenting classloader. the game is not decompiled at all, other than giving you something to look at in the IDE.

If you can't use the API, I suggest you to use Mixins or really asking yourself if your idea should worth the instability/effort of creating a coremod.

see spongepowered's mixin wiki

For accessing a decompiled minecraft source, I think the easiest way is to grab something people use to write mods (like the fabric example mod or the quilt template mod or the forge getting started guide), open it in an IDE like eclipse or intellij, then just don't write a mod and click around in the source instead. Keep the copyrights in mind

If you're making a fabric mod, then you can just use the Fabric Example Mod as template

This is the template I used, and this is what I used to setup the enviroment, I already coded an item into the mod and it all works, but when I go onto the debug tab on the left and run the code, it opens a new game rather than giving me a share-able .jar file I can drag in myself.

You need to go back to the example mod page, and start again from the 1.18 template. There's a dropdown in the top left to switch between versions. If you can't find it, here's a direct link.

Get an IDE you like (I recommend IntelliJ IDEA community with the Minecraft Dev plugin) and download/fork the example mod. That'll give you a good base

Hello, I am trying to create a Minecraft mod with Visual Studio Code using the template provided by Fabric (https://github.com/FabricMC/fabric-example-mod/tree/1.17). When running the mod in the VS Code testing environment both with and without debugging, it works just as expected. However, when I compile it into a jar file and put it into a normal Fabric 1.17.1 installation, Fabric does not seem to recognize it as a mod and just launches without it. Additionally, when I open the jar with 7-zip, there does not seem to be anything specific to the mod. There are no .class files from my code and no assets. It is as if the compiler just puts in the base components, and cannot find the source code or assets. The mod is for 1.17.1. Any help would be appreciated. Thank you.

Are you using the template https://github.com/fabricmc/fabric-example-mod

I started modding using Fabric; specifically a combination of the tutorial on the wiki, reading how other mods do stuff, and asking on the Discord. Once you're familiar with how Minecraft works internally using one mod-loader it's easy enough to transfer to the others (or multiple at once, using Architectury as pointed out), but I wouldn't start off with this. The example mod also gets you a setup you can modify at will.

I've been trying to use this the example mod from github for hours, but I just cannot get it to work. I keep receiving a "build failed" error on startup (something like "filename: failed") with no context to go off of. I have downloaded Java, and Intellij works fine for other coding projects. I have no idea what is causing this.